Apparatus for accelerating the pick stroke at a loom



March 29, 1966 H. SCHMID 3,242,950

APPARATUS FOR ACGELERATING THE PICK STROKE AT A LOOM Filed March 9, 1964 5 Sheets-Sheet 1 Fig.7

INVENTOR. HeiNRi H Sd-mil B Y UM 1 (M A TTORNEY March 29, 1966 H. SCHMID 3,242,950

APPARATUS FOR AQCELERATING THE PICK STROKE AT A 1100M Filed March 9, 1964 5 Sheets-Sheet z INVENTQR. Ha'ma'l l'r Sal-mil BYWMU A TTORNEY March 29, 1966 H. sc M 3,242,950

APPARATUS FOR AGCELERATING THE PICK STROKE AT A LOOM Filed March 9, 1964 5 Sheets-Sheet 5 Fig. 3

as f 3 m 0 I E, t 25 {a 20 k I s 4" \M .s ,v 4: 10 In/V VF SI t o 0 so 100 use 200 250 500 0/5tance 0r have] of shuttle INVENTOR. HElNKich SGFMEJ ATWLIM A TTORNE Y United States Patent 3,242,950 APPARATUS FOR ACCELERATING THE PICK STROKE AT A LGOM Heinrich Schmid, Rapperswil, St. Gallen, Switzerland Filed Mar. 9, 1964, Ser. No. 350,425 Claims priority, application Switzerland, Mar. 12, 1963, 3,123/63 10 Claims. (Cl. 139-147) The present invention has reference to an improved apparatus for accelerating the pick stroke at a loom.

A number of different apparatus are already known to the art which impart to the picker stick an additional acceleration for the picking operation. Such an apparatus, for example, exhibit means which during the picking operation are capable of imparting to the picking cam or eccentric an increased angular velocity with respect to the drive shaft. As a result, the shuttle is the recipient of a larger pick energy and an increased initial velocity permitting the same to undertake its path of travel in shorter time and still emerge from the shed with suflicient energy.

The increase of the initial velocity of the shuttle is particularly then of importance when it is desired to increase the efficiency of the loom. In so doing, however, there must be taken care that the picker stick after initiating a pick has available a suflicient path for braking, that is, that the increase of velocity does not occur at the expense of the brake path, since in consequence of the larger terminal velocity a larger quantity of energy must be destroyed.

It is, therefore, a primary object of the present invention to provide an improved apparatus for accelerating the pick stroke while fulfilling these aforementioned requirements and nonetheless is in a position to bring about an increase in efliciency.

The inventive apparatus arranged at a loom, by means of which the picker stick is actuated through the intermediary of a lug strap or pulling member, with such lug strap being operably connected with a picking eccentric, is characterized by the features that a lever is arranged between the lug strap and the picker stick, at one portion of which there engages the aforesaid lug strap and another portion of which cooperates with the picker stick, and wherein the distance between the fulcrum of the aforesaid lever and the point of engagement of said lug strap with said lever over at least a portion of the travel of said lever forms a shorter effort lever arm with respect to the picker stick, than the effort lever arm of said picker stick if the lug strap acted directly upon said picker stick, in order to additionally accelerate the picker stick through this aforesaid portion of the travel of said lever.

Other features, objects and advantages of the invention will become apparent by reference to the following detailed description and drawings in which:

FIGURE 1 illustrates a preferred embodiment of the inventive picking system in the starting position of the picker stick;

FIGURE 2 illustrates the picking system of FIGURE 1 in the position at the period of time of which there appears the largest picker stick velocity; and

FIGURE 3 is a time-distance diagram for the picker.

Describing now the drawings and, in particular, with reference now initially made to FIGURES 1 and 2, it should 'be appreciated that reference numeral 1 designates a loom frame or shield in which there is mounted a drive shaft 2 and a rock shaft 3. A picking eccentric or cam 4 is seated upon the drive shaft 2 and upon which travels a picking roller 5 ro-tatably mounted to a lever 6. The lever 6 is operably connected with a picking Patented Mar. 29, 1966 "ice shaft 7 which is mounted in any suitable non-illustrated manner at the loom shield or frame 1 and carries a picker arm 8. In known manner, a lug connection or pulling loop means 9 is secured at 8a to the picker arm 8. This lug connection means 9 comprises a lug stick 9a and a lug or pulling strap 912. A picker support or carrier 10 is connected to the rock shaft 3-, in known manner partaking in the oscillating movements of such shaft 3 and provides a rocking surface for a picker shoe member 11. The picker stick 12 is connected in known manner to the picker shoe member 11, whereby the latter in likewise known manner is secured to the picker support 10.

The lug strap 9b of lug connection means 9 encircles picker stick 12 which carries a picker 13- at its upper end. Picker 13 acts upon a shuttle 15' to move it across the sley 14. Moreover, an acceleration lever 17 is articulated at its upper end 17a to the picker stick 12 through the agency of flange means 16. This acceleration lever 17 is likewise encircled by the lug strap 9b of lug connection means 9, and, more specifically, between two stops 18 fixedly clamped to the aforesaid acceleration lever 17.

An auxiliary support or carrier 20 is connected through the intermediary of a plate 19 with the picker support 10, the opposite end of which is adjustable via a spindle 21 with respect to an extension 22 of the picker support 10. At the right hand side of the end of the auxiliary support 20 there is connected a pressure spring 23 which presses against the lower end of the acceleration lever 17 and has the tendency to maintain such in the starting position L parallel to the picker stick 12 (see FIGURE 1). In so doing, the free end 17b of the acceleration lever 17 bears against a stop 24 pivotally connected at 25 to the auxiliary carrier 20. It will be understood that during operation of the device the stop 24 is not movable along the support 20, rather is only pivotable about location 25. However, if desired, provision could be made to selectively position the stop 24 at any desired location along such support, but once such selection is made then during the operation of the device such stop 24 only carries out pivotal movements. A tension spring 26 is suspended at one of its ends at a pin 26a provided at the stop 24 and at its other end at the extension 22, having the tendency to normally urge such stop 24 into the position depicted in FIGURE 1. It will be appreciated that the lower end 1712 of lever 17 tends to pivot the stop 24 in counterclockwise direction. However, such pivoting movement is prevented by the pin 26a provided at the stop 24 since this pin bears against the underface of the support 20. Stop 24 normally assumes the position of FIGURE 1 since the tension spring 26 exerts a force upon the stop 24 which is directed downwardly to the right of FIGURE 1, tending to keep the pivot point 25, the pin 26a to which one end of spring 26 is connected and the other end 26b of said spring in a substantially straight line, and thus the stop 24 in this normal position of FIGURE 1 at, which it provides a fulcrum for the lower end 17b of lever 17. This fulcrum temporarily restrains the lower end 1712 of lever 17 so that during the first phase of the movement of the picker stick to the left of FIGURE 1 said lever 17 pivots at its upper end 17a with respect to picker stick 12 and initially trails this picker stick 12 until it is lifted over the stop 24, as shown in FIGURE 2. Moreover, the picker stick 12 and acceleration lever 17 are surrounded by a leather band 27, whereby such leather band limits the degree of deflection of the lower free end 17b of the acceleration lever 17 relative to the picker stick 12 (see FIGURE 2).

As previously mentioned, the picking system depicted.

in FIGURE 1 is shown therein at its starting position, whereby the picker stick 12 assumes the position L. With rotation of the drive shaft 2 the picking cam surface at the picking eccentric or cam 4 moves beneath the picking roller 5, thereby pivoting the levers 6 and 8 about the axis of the picking shaft 7. In consequence thereof the lug strap 9b is displaced towards the left. As soon as this lug strap 912 has moved through the so-called inactive or dead-motion position H it comes to bear against the acceleration lever 17. Since the lower end 17b of this acceleration lever 17 bears against the stop member 24, the aforesaid lever shifts about a point or fulcrum which is determined by the position of the aforesaid stop, whereby the resulting pivotal motion of the lever 17 with respect to the picker stick 12 (FIGURE 2) is transmitted via the flange means 16 at the upper end of the same to the picker stick 12.

The loom shuttle 15 is thus placed into motion through the agency of the picker 13. The movement imparted to the loom shuttle 15 via the picker 13 corresponds-considered apart from the movement of the lug strap 9b in accordance with the course of the curve of the picking eccentric 4to the relationship a C F The distance A between the point of attack K of the lug strap 9b and the stop 24 (fulcrum of the acceleration lever 17) corresponds to the so-called driving or effort lever arm, whereas the driven or load lever arm at this aforesaid acceleration lever 17 corresponds to the distance C. The acceleration lever 17 delivers its force to the picker stick 12 via the flange means 16. The lever arm relationship of the picker stick 12 is thus the sum of the distances B-l-D for the driving lever arm and the distance F for the driven lever arm. The total lever arm relationship in accordance with the above-mentioned relationship provides an acceleration for the picker 13, so that the latter reaches the point M sooner (-FIGURE 2)--in which the highest point of the curve at the picking eccentric 4 is crossedthan if lug strap 9b were to act directly upon the picker stick 12 and the lever arm relationship D:F were effective.

Such can be readily ascertained from FIGURE 2 wherein the path or travel difference As at the picker 13 is designated. The phantom line position of the picker stick 12 and picker 13 thus corresponds to that position which these elements in the same period of time would assume if they were directly actuated by the lug strap 911, that is without interconnection of the acceleration lever 17. The path difference As is thus an expression for the larger average velocity of the picker stick 12 between the starting position L and the position of largest velocity M. Since the movement or travel of the picker stick 12 and the picker 13 after passing position M is retarded or delays, the weaving shuttle 15 is freed from the aforesaid picker 13 and begins its travel through the weft path, in other words across the sley. The picker stick 12 which has completed its travel to point N (phantom line position of picker stick 12 and picker 13), during its displacement pulls the acceleration lever 17 over the stop 24. Under the action of the lug strap 9b the acceleration lever 17 thus comes to bear at the picker stick 12 and both members in synchronism reach the terminal position N, in which the picker stick 12 strikes the buffer or bumper leather member 28. The return of the picker stick 12 into its starting position takes place in known manner, whereby the lower end 17b of the acceleration lever 17 slides past the yielding stop 24 and, thus, likewise again assumes the starting position depicted in FIG- URE 1. It is to be noted that the spacing between the position M and the terminal position N must not be increased in spite of the higher acceleration of the pick.

Now, from the time-distance diagram of FIGURE 3, depicting the travel of the shuttle as a function of the picking-time, the curve for the picker motion for the inventive picking system is represented in full lines and for a known system in dotted lines. Thus, from this diagram there can be readily seen that the shuttle with the inventive picking system can move through an equal or like path within a shorter time than with the known picking system. The point M thus corresponds to the position in which the shuttle leaves the picker. It is further to be appreciated that the described apparatus can also be employed in conjunction with a picker stick incorporating a stationary fulcrum or point of rotation, that is without a picker shoe.

While there is shown and described a present preferred embodiment of the invention it is to be distinctly under stood that the invention is not limited thereto but may be otherwise variously embodied and practiced within the scope of the following claims.

What is claimed is:

1. Apparatus for driving a picker stick in a loom, comprising a picker stick, lug connection means for actuating said picker stick, picking eccentric means operably cooperating with said lug connection means, said lug connection means including a lug strap, a lever cooperating with said picker stick and said lug connection means, said lever having a portion thereof engaged by said lug strap and a further portion articulated to said picker stick, stop means cooperating with said lever positioned to provide a temporary fulcrum for said lever, said stop means temporarily restraining an end of said lever remote from said further portion until said lever has moved through a given portion of its travel, so that during such time as said remote end of said lever is restrained said lever is pivoted with respect to said picker stick and trails the latter during movement through said given portion of its travel.

2. Apparatus for driving a picker stick in a loom, comprising a picker stick, lug connection means for actuating said picker stick, picking eccentric means operably cooperating with said lug connection means, said lug connection means including a lug strap, a lever cooperating with said picker stick and said lug connection means, said lever having a portion thereof engaged by said lug strap and a further portion articulated to said picker stick, stop means mounted for pivotal movement cooperating with said lever and positioned to provide a temporary fulcrum for said lever, a tension spring effective at said stop means to normally urge the latter into its starting position.

3. Apparatus for driving a picker stick in a loom, comprising a picker stick, lug connection means for actuating said picker stick, picking eccentric means operably c0- operating with said lug connection means, said lug connection means including a lug strap, a lever cooperating with said picker stick and said lug connection means, said lever having a portion thereof engaged by said lug strap and a further portion directly cooperating with said picker stick, means providing a temporary fulcrum for restraining said lever through a portion of its travel so that it trails and propels said picker stick at an accelerated rate during said portion of said travel of said lever.

4. Apparatus for driving a picker stick in a loom as defined in claim 3 wherein said further portion of said lever is articulated to said picker stick, said temporary fulcrum providing means comprising stop means cooperating with said lever.

5. Apparatus for driving a picker stick in a loom as defined in claim 4 further including a picker shoe provided for said picker stick, a support member for said picker shoe, and a carrier arranged above said support member to which is mounted said stop means.

6. Apparatus for driving a picker stick in a loom, comprising a picker stick, lug connection means for actuating said picker stick, picking eccentric means operably cooperating with said lug connection means, said lug connection means including a lug strap, a lever cooperating with said picker stick and said lug connection means, said lever having a portion thereof engaged by said lug strap and a further portion directly cooperating with said picker stick, means providing a temporary fulcrum for restraining said lever through a portion of its travel so that it trails and propels said picker stick at an accelerated rate during said portion of said travel of said lever.

7. Apparatus for driving a picker stick in a loom, comprising a picker stick mounted for pivoting about a given point of rotation, lug connection means for actuating said picker stick, picking eccentric means operably cooperating With said lug connection means, said lug connection means including a lug strap, a rigid lever cooperating with said picker stick and said lug connection means, said picker stick and said rigid lever being in substantial parallelism in the starting position of said picker stick and rigid lever, said rigid lever having a portion thereof engaged by said lug strap and a further portion cooperating with said picker stick, means providing a temporary fulcrum for restraining said rigid lever through a portion of its travel so that it trails and propels said picker stick at an accelerated rate during said portion of said travel of said rigid lever.

8. Apparatus for driving a picker stick in a loom, comprising a picker stick mounted for pivoting about a given point of rotation, lug connection means for actuating said picker stick, picking eccentric means operably cooperating with said lug connection means, said lug connection means including a lug strap, a lever cooperating with said picker stick and said lug connection means, said picker stick and said lever being in substantial parallelism in the starting position of said picker stick and lever, said lever and said picker stick each having a portion thereof encircled by said lug strap, said portion of said lever being directly engaged by said lug strap, said lever having one end pivotably connected to said picker stick, means providing a temporary fulcrum for restraining the other end of said lever through a portion of its travel so that it trails and propels said picker stick at an accelerated rate during said portion of said travel of said lever.

9. Apparatus for driving a picker stick in a loom as defined in claim 8 wherein said means providing said temporary fulcrum comprises stop means mounted for pivotal movement, said stop means releasing said other end of said lever after the latter has moved through said portion of its travel.

10. Apparatus for driving a picker stick in a loom, as defined in claim 9 further including a tension spring effective at said stop means to normally urge the latter into its starting position.

References Cited by the Examiner FOREIGN PATENTS 4/ 1950 Great Britain. 3/ 1952 Switzerland. 

1. APPARATUS FOR DRIVING A PICKER STICK IN A LOOM, COMPRISING A PICKER STICK, LUG CONNECTION MEANS FOR ACTUATING SAID PICKER STICK, PICKING ECCENTRIC MEANS OPERABLY COOPERATING WITH SAID LUG CONNECTION MEANS, SAID LUG CONNECTION MEANS INCLUDING A LUG STRAP, A LEVER COOPERATING WITH SAID PICKER STICK AND SAID LUG CONNECTION MEANS, SAID LEVER HAVING A PORTION THEREOF ENGAGED BY SAID LUG STRAP AND A FURTHER PORTION ARTICULATED TO SAID PICKER STICK, STOP MEANS COOPERATING WITH SAID LEVER POSITIONED TO PROVIDE A TEMPORARY FULCRUM FOR SAID LEVER, SAID STOP MEANS TEMPORARILY RESTRAINING AN END OF SAID LEVER REMOTE FROM 